Field of the Invention
The embodiments disclosed herein relate to a power convertor, a controller, and a method for changing a carrier frequency.
Discussion of the Background
Examples of PWM-control power convertors include inverters, convertors, and matrix convertors.
Japanese Unexamined Patent Application Publication No. 2001-37248 discloses an inverter that involves changing carrier cycle in PWM control in accordance with a control deviation, in an attempt to enhance control responsiveness. Specifically, the inverter generates a cyclic modulation coefficient that is inversely proportionate to the absolute value of a current control deviation, which is a current deviation between a current command and a current detection value. The inverter uses the cyclic modulation coefficient to change carrier frequency and gain of current control.